Clear warning on missing assignment operator

modarith.h

@@ -26,15 +26,17 @@ CRYPTOPP_DLL_TEMPLATE_CLASS AbstractRing<Integer>;
 CRYPTOPP_DLL_TEMPLATE_CLASS AbstractEuclideanDomain<Integer>;
 
 /// \brief Ring of congruence classes modulo n
-/// \details This implementation represents each congruence class as the smallest
+/// \details This implementation represents each congruence class as
-///   non-negative integer in that class.
+///  the smallest non-negative integer in that class.
-/// \details <tt>const Element&</tt> returned by member functions are references
+/// \details <tt>const Element&</tt> returned by member functions are
-///   to internal data members. Since each object may have only
+///  references to internal data members. Since each object may have
-///   one such data member for holding results, the following code
+///  only one such data member for holding results, you should use the
-///   will produce incorrect results:
+///  class like this:
-///   <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
-///   But this should be fine:
 ///  <pre>    abcd = group.Add(a, group.Add(b, group.Add(c,d));</pre>
+///  The following code will produce incorrect results:
+///  <pre>    abcd = group.Add(group.Add(a,b), group.Add(c,d));</pre>
+/// \sa <A HREF="https://cryptopp.com/wiki/Integer">Integer</A> on the
+///  Crypto++ wiki.
 class CRYPTOPP_DLL ModularArithmetic : public AbstractRing<Integer>
 {
 public:
@@ -255,6 +257,10 @@ public:
 
 	static const RandomizationParameter DefaultRandomizationParameter;
 
+private:
+	// Squash warning on missing assignment operator.
+	ModularArithmetic& operator=(const ModularArithmetic &ma);
+
 protected:
 	Integer m_modulus;
 	mutable Integer m_result, m_result1;